The Swarm electric field instruments (EFI) comprise a pair of thermal ion imagers (TII) for measuring properties of the ionospheric thermal ions (drift and temperature), a pair of Langmuir probes (LP) for measuring electron temperature and ion (practically, electron) density, and a fixed-bias planar Langmuir probe (faceplate) for measuring ion density. Using data from these instruments, the Swarm LP Ion Drift and Effective Mass (SLIDEM) project will augment Swarm's ability to measure the along-track component of ion drift, and assess the composition of ionospheric ions.
This project develops the framework for implementing a Level 2 along-track ion drift and effective ion mass data product for the Swarm PDGS data processing chain. Methods will be refined for deriving the data products, validating the product using independent datasets, models, and particle-in-cell simulations, and delivering a first release of the data based on historical Swarm EFI measurements. An operational Level 2 scheme will be demonstrated for routine processing of the latest EFI data and reprocessing of the entire mission dataset when needed. The new dataset has the potential to benefit scientific investigations of ionospheric ion drift, electric field, ion composition, and related studies (e.g., mass and energy conservation), as well as for validating the TII along-track drift estimates.
Project duration: June 2020 – July 2022. This project is funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-124.